feat: add linter with formatting rules, duplicate detection, sorting, and auto-fix

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/linter/linter_test.go

@@ -0,0 +1,111 @@
+package linter
+
+import (
+	"testing"
+
+	"github.com/veggiemonk/awesome-docker/internal/parser"
+)
+
+func TestRuleDescriptionCapital(t *testing.T) {
+	entry := parser.Entry{Name: "Test", URL: "https://example.com", Description: "lowercase start.", Line: 10}
+	issues := CheckEntry(entry)
+	found := false
+	for _, issue := range issues {
+		if issue.Rule == RuleDescriptionCapital {
+			found = true
+		}
+	}
+	if !found {
+		t.Error("expected RuleDescriptionCapital issue for lowercase description")
+	}
+}
+
+func TestRuleDescriptionPeriod(t *testing.T) {
+	entry := parser.Entry{Name: "Test", URL: "https://example.com", Description: "No period at end", Line: 10}
+	issues := CheckEntry(entry)
+	found := false
+	for _, issue := range issues {
+		if issue.Rule == RuleDescriptionPeriod {
+			found = true
+		}
+	}
+	if !found {
+		t.Error("expected RuleDescriptionPeriod issue")
+	}
+}
+
+func TestRuleSorted(t *testing.T) {
+	entries := []parser.Entry{
+		{Name: "Zebra", URL: "https://z.com", Description: "Z.", Line: 1},
+		{Name: "Alpha", URL: "https://a.com", Description: "A.", Line: 2},
+	}
+	issues := CheckSorted(entries)
+	if len(issues) == 0 {
+		t.Error("expected sorting issue")
+	}
+}
+
+func TestRuleSortedOK(t *testing.T) {
+	entries := []parser.Entry{
+		{Name: "Alpha", URL: "https://a.com", Description: "A.", Line: 1},
+		{Name: "Zebra", URL: "https://z.com", Description: "Z.", Line: 2},
+	}
+	issues := CheckSorted(entries)
+	if len(issues) != 0 {
+		t.Errorf("expected no sorting issues, got %d", len(issues))
+	}
+}
+
+func TestRuleDuplicateURL(t *testing.T) {
+	entries := []parser.Entry{
+		{Name: "A", URL: "https://example.com/a", Description: "A.", Line: 1},
+		{Name: "B", URL: "https://example.com/a", Description: "B.", Line: 5},
+	}
+	issues := CheckDuplicates(entries)
+	if len(issues) == 0 {
+		t.Error("expected duplicate URL issue")
+	}
+}
+
+func TestValidEntry(t *testing.T) {
+	entry := parser.Entry{Name: "Good", URL: "https://example.com", Description: "A good project.", Line: 10}
+	issues := CheckEntry(entry)
+	if len(issues) != 0 {
+		t.Errorf("expected no issues, got %v", issues)
+	}
+}
+
+func TestFixDescriptionCapital(t *testing.T) {
+	entry := parser.Entry{Name: "Test", URL: "https://example.com", Description: "lowercase.", Line: 10}
+	fixed := FixEntry(entry)
+	if fixed.Description != "Lowercase." {
+		t.Errorf("description = %q, want %q", fixed.Description, "Lowercase.")
+	}
+}
+
+func TestFixDescriptionPeriod(t *testing.T) {
+	entry := parser.Entry{Name: "Test", URL: "https://example.com", Description: "No period", Line: 10}
+	fixed := FixEntry(entry)
+	if fixed.Description != "No period." {
+		t.Errorf("description = %q, want %q", fixed.Description, "No period.")
+	}
+}
+
+func TestLintDocument(t *testing.T) {
+	doc := parser.Document{
+		Sections: []parser.Section{
+			{
+				Title: "Tools",
+				Level: 2,
+				Entries: []parser.Entry{
+					{Name: "Zebra", URL: "https://z.com", Description: "Z tool.", Line: 1},
+					{Name: "Alpha", URL: "https://a.com", Description: "a tool", Line: 2},
+				},
+			},
+		},
+	}
+	result := Lint(doc)
+	if result.Errors == 0 {
+		t.Error("expected errors (unsorted, lowercase, no period)")
+	}
+}